Improvements in manufacturing technology and materials are the keys to increased performance and reduced costs for many articles. As an example, continuing and often interrelated improvements in processes and materials have resulted in major increases in the performance of aircraft gas turbine engines. One of the most demanding applications for materials can be found in the components used in aircraft jet engines. By operating at higher temperatures, the engine can be made more efficient in terms of lower specific fuel consumption while emitting lower emissions. Thus, improvements in the high temperature capabilities of materials designed for use in aircraft engines can result in improvements in the operational capabilities of the engine.
Non-traditional high temperature materials such as ceramic matrix composites as structural components have been employed in gas turbine engines. For several decades, composites, such as CMC, have been investigated for a wide range of applications. One aspect of the investigation has been the means by which those composite materials can be accommodated in a metallic structure, given the inherent limitations of the composite materials with regard to high local contact stresses, and the substantial difference between composite and metallic structure thermal expansion coefficients. Carried out were development, analysis, fabrication, and testing activities for a range of composite materials and applications of same, including carbon-carbon, CMC, and mixed composition ceramics and ceramic composite materials, and development and demonstration of multiple methodologies that provided compliance and sealing between the composite and metallic structures.
Such means would be in demand for the location and retention of, and sealing, advanced high temperature composite structures such as CMC. With no limitation, those means are believed to be useful in turbine blade tracks, where they provide a compliant interface between the composite structure and the metallic supporting structure and also provide locating features to maintain the position of said structure and secure sealing cooling air leakage between those components.
Some existing systems have various shortcomings, drawbacks, and disadvantages relative to certain applications. Accordingly, there remains a need in industry for the means which would allow for mitigating the high local stresses that can arise from contact between composite and metal structures. In the present novel disclosure, it is achieved via a spring arrangement resulting in load redistribution that leads to reduced local contact stresses, and by which sealing around the CMC structure to control cooling air leakage is provided.